sudo apt update
sudo apt upgrade
sudo apt install-y certbot

sudo certbot certonly --standalone

Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator standalone, Installer None
Enter email address (used for urgent renewal and security notices)(Enter 'c' to
cancel): hoge@bathtimefish.com

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Please read the Terms of Service at
https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf. You must
agree in order to register with the ACME server at
https://acme-v02.api.letsencrypt.org/directory
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
(A)gree/(C)ancel: A

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Would you be willing to share your email address with the Electronic Frontier
Foundation, a founding partner of the Let's Encrypt project and the non-profit
organization that develops Certbot? We'd like to send you email about our work
encrypting the web, EFF news, campaigns, and ways to support digital freedom.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
(Y)es/(N)o: Y

lease enter in your domain name(s)(comma and/or space separated)(Enter 'c'
to cancel): letsencrypttest.bathtimefish.com

Obtaining a new certificate
Performing the following challenges:
http-01 challenge for letsencrypttest.bathtimefish.com
Waiting for verification...
Cleaning up challenges

IMPORTANT NOTES:
 - Congratulations! Your certificate and chain have been saved at:
   /etc/letsencrypt/live/letsencrypttest.bathtimefish.com/fullchain.pem
   Your key file has been saved at:
   /etc/letsencrypt/live/letsencrypttest.bathtimefish.com/privkey.pem
   Your cert will expire on 2021-07-03. To obtain a new or tweaked
   version of this certificate in the future, simply run certbot
   again. To non-interactively renew *all* of your certificates, run
   "certbot renew"
 - Your account credentials have been saved in your Certbot
   configuration directory at /etc/letsencrypt. You should make a
   secure backup of this folder now. This configuration directory will
   also contain certificates and private keys obtained by Certbot so
   making regular backups of this folder is ideal.
 - If you like Certbot, please consider supporting our work by:

   Donating to ISRG / Let's Encrypt:   https://letsencrypt.org/donate
   Donating to EFF:                    https://eff.org/donate-le

sudo ls /etc/letsencrypt/live/letsencrypttest.bathtimefish.com
README  cert.pem  chain.pem  fullchain.pem  privkey.pem

sudo apt install-y nodejs npm
sudo npm i -g n
sudo n latest
sudo npm i -S typescript ts-node 
sudo apt remove nodejs
sudo apt autoclean

mkdir-p ./work &&cd$_
npm i -S fastify
npm i -D @types/node
npx tsc --init

import*asfsfrom'fs';import*ashttp2from'http2';importfastifyfrom'fastify';constcertPath='/etc/letsencrypt/live/letsencrypttest.bathtimefish.com';constserver=fastify({logger:true,http2:true,https:{key:fs.readFileSync(`${certPath}/privkey.pem`),cert:fs.readFileSync(`${certPath}/fullchain.pem`)},});server.get('/',function(request,reply){reply.code(200).send({hello:'world'});});server.listen(443,'0.0.0.0',(err,address)=>{if(err){console.error(err);process.exit(1);}});

sudo ts-node index.ts

curl https://letsencrypttest.bathtimefish.com/
{"hello":"world"}